Are there bottoms to the stock tanks?

Yes. They are Rubbermaid food safe poly stock tanks and I’ve drilled holes in the bottom of them and they are on cement blocks.

With a solid bottom, these are just large containers (not raised beds) and for best results, you need to fill them with a soil mix designed for growing in containers. Not garden soil, compost or shredded leaves but a soil-less mix intended specifically for container culture. Other materials are too dense and heavy and will result in very poor drainage, lack of proper aeration and a high perched water table.

And as with any other container grown plantings, these will need to be fertilized often with a water soluble or liquid fertilizer.

^^ All true.

But to answer the original questions: Leaves have a lot of nutrients, but are low in nitrogen as you already know. Yes you can use either leaves or leaves + greens mix as mulch. It's exactly what I use on my tomatoes and peppers. By fall it's usually decomposed. It's kind of a combination of mulching and sheet composting. Browns, either by themselves or mixed with greens, if laid on top of the soil as mulch, will not deplete nitrogen in the soil. They only take longer to decompose if they have to pull N from the air instead of from greens mixed in.

You may not need a ton of fertilizer in the beds considering what you have in there already - i.e. a high percentage of compost.

Not "beds"......containers :-) And there is not enough of a nutrient concentration in compost to keep high demand edibles happy and growing and producing well. And no amount of mulching in a container situation is going to help that!!

Well, whatever works. But I'll throw my lot in with GardenGal - you may run in to a problem because you are trying to do organic gardening in containers.

Organic culture depends on a wide variety of life in the soil, from microbes to beetles and worms. Enclosed containers can't support the same diversity of organisms that garden soil can. So you may put leaves in the containers, but unless you have the full complement of insects, bacteria and fungi to break it down, the plants will never get the nutrients in the form that they need.

That's why most gardeners approach containers as a synthetic environment. The soil isn't there to provide nutrients, rather it is chosen for it's ability as a rooting medium and to provide air and proper moisture drainage for the plant. Then you add the nutrients in a liquid synthetic fertilizer. You strictly control to provide the exact nutrients the plant needs - no waiting around hoping the right fungus kicks in to break things down.

Now, you don't have to do it that way - I am just laying out why many gardeners use organic methods in the garden and synthetics in their containers.

>>toxcrusadr.......so you're saying I can, say, mix grass cuttings with shredded leaves and just lay them under my tomato plants?

Yes that's what I'm saying. But what others are saying is also true: you're going to need some fertilizer for those containers. Doesn't take a lot but it will make a difference.

And I would counter that anything grown in a container will need routine and frequent fertilization!! Every time you water these containers, nutrients will be flushed out and they need to be replaced!! I would not rely on the nutrients available from just whatever organic matter the containers are filled with. They will not offer enough nor will they be as readily available in a container situation as they would with growing the same plants in the ground, for the reasons Richard Brennan explained so clearly upthread!

Growing in containers - which is precisely what these stock tanks are - is very different from growing in the ground. And all aspects of it must be approached differently if you expect to have equal success.

Thanks everyone. I do understand what you all are saying, and to be honest, I'm sad that I had to resort to stock tank gardens for most of my stuff. But I may have to make some compromise in my fertilization, or I'll end up with not very good results. Should I visit the organic gardening forum, or do any of you know of the least toxic fertilizer I could use on these containers? I've seen "organic" fertilizers out there, but I'm uneducated on if there are things even in those that I should avoid.

I appreciate all your input!

No fertilizers are "toxic"!! But if you want to stay organic, look for something like fish or seaweed emulsion or one of the newer liquid organics on the market. Not ideal but sufficient for most purposes :-) Just stay away from the dry or granular forms....they will not work well for you.

Thanks gardengal!

I garden in containers using homemade potting soil made mostly of composted wood chips, with peat moss and diatomaceous earth. (sweeping compound I get at the autoparts store)---not fuller's earth, which seems to be also sold at the autoparts store. Diatomaceous earth. I put the rougher stuff from the compost pile including uncomposted sticks on the bottom, run of the pile stuff in the middle and 1/4 inch sifted stuff up top. Lately I've been skipping the peat almost entirely.

Get a soil test. Umass Amherst charges $20 for a container soil test with an N test. Well worth the $5 premium for the N test. Be sure and use the right form, the one for greenhouse growing media.

I'm not organic, so I don't know how you address micronutrient deficiencies like a Copper or Zinc deficiency organically. Probably seaweed, mostly.

I haven't had a problem with "perched water." In my particular microclimate, water tends to flow downhill and thus, drain from the container. It also evaporates rather than perching.

P.S. avoid the temptation to argue with the soil test. Avoid the temptation to rationalize away the soil test and do what you want. If it turns out you have a Phosphorus and Boron deficiency for example, then address the Phosphorus and Boron deficiency.

Thanks kokopellifivea. I'll check that out.

Catherine - Pam is correct in noting that you're just growing in big pots. I think you'd have been better served if you drilled some large holes (4" or so) in the bottom and set the tanks right on the ground. That simple difference changes the tanks from a container to a raised bed - hydrologically speaking. By making sure there is an unbroken soil column between the growing medium in the tank and the soil beneath it (the earth), you have the benefit of the earth acting as a giant wick, assuming there isn't a drainage problem with the natural soil beneath the tanks. Alternately, you could keep them at the same ht, but fill the space between what supports the tanks with sand, then set the tanks on the sand. You could even use a piece of corrugated poly pipe for septic fields to ensure contact between the soil in the tank and the sand, in case the sand wants to settle.

Growing in a raised bed allows you to use soils that would be too water-retentive for use in a container. Based on the soil ingredients you listed, I'm afraid excess water retention might raise its head as an adversary. Soil saturation tends to minimize populations of nitrifying bacteria; this, + a high % of organic matter in the soil can lead to your plants taking up N in ammoniacal form, which can damage cells via ammonium toxicity. Ammonium toxicity is very common in container culture, especially when the soil is lacking O2 (as when it's compacted or saturated), and is rarely diagnosed correctly.

Al